There is provided an electric-power conversion apparatus including a chopper circuit; a current sense resistor that detects the output current of the chopper circuit; a differential detection circuit that outputs, as a differential detection signal (vo), the electric potential difference across the current sense resistor; and a calculation means that corrects the differential detection signal (vo) from the differential detection circuit by use of a control signal (D1) for the chopper circuit so as to calculate the output current (i0) of the chopper circuit.